Sole and heel of rubber or plastic

ABSTRACT

The invention concerns a rubbery or plastic sole having a tread profile with at least one essentially longitudinal rib at a distance from the sole edge, and is characterized by transverse and/or inclined ribs that branch off said longitudinal rib and/or the central line of the sole, towards the tip of the shoe or form an angle Alpha of not more than 90* wherein said transverse and/or inclined ribs embrace grooves not communicating with each other. These grooves may be bent, have varying depth and/or width over their length, and have arcuate or semicircular cross section; transverse and/or inclined ribs may ramify; longitudinal ribs may be provided at the edge of the sole.

United States Patent 51 May 16, 1972 Schwab [54] SOLE AND HEEL OF RUBBEROR PLASTIC [72] Inventor: Johann Schwab, Vienna, Austria [73] Assignee:Semperit Osterreichisch-Amerikanisde Gummiwerke Aktiengesellschaft,Vienna, Austria [22] Filed: Jan. 28, 1970 [21] Appl. N0.: 6,348

[30] Foreign Application Priority Data Jan. 28, 1969 Austria ..A 863/69[52] U.S. C1. ..36/59 C [51] Int. Cl. ..A43b 13/18 [58] Field of Search..36/59 C, 32; D2/32O [56] References Cited UNITED STATES PATENTS2,162,912 6/1939 Craver ..36/59 C D120,3l6 4/1940 Reeves ..D2/320D124,794 1/1941 Kavenagh et a1 ..D2/320 2,229,406 l/l94l Cutler ..36/59C 2,941,316 6/1960 Hack ..36/32 X FOREIGN PATENTS OR APPLICATIONS TheSunday Star, Washington DC, May 10, 1959 Advertisement, page A-24.

Primary Examiner-Alfred R. Guest Attorney-Werner W. Kleeman [57]ABSTRACT The invention concerns a rubbery or plastic sole having a treadprofile with at least one essentially longitudinal rib at a distancefrom the sole edge, and is characterized by transverse and/or inclinedribs that branch off said longitudinal rib and/or the central line ofthe sole, towards the tip of the shoe or form an angle a of not morethan 90 wherein said transverse and/or inclined ribs embrace grooves notcommunicating with each other. These grooves may be bent, have varyingdepth and/or width over their length, and have arcuate or semicircularcross section; transverse and/or inclined ribs may ramify; longitudinalribs may be provided at the edge of the sole.

8 Claims, 19 Drawing Figures PATENTEUMAY 16 m2 3, 662,478

sum 02 0F 11 PATENTEUMM 16 I972 saw on HF 11 ZINE/V7019. 751mm6111/44/45 0770mm y PATENTEDMAY 16 I972 SHEET 0? or 11 PATENTEDMM 161972 sum 08 0F 11 Fig. 16

0 6 MAW WM 0 W q 0 WM m PATENTEDMAY 16 I972 sum 11 [1F 11 Fig. 19

SOLE AND HEEL OF RUBBER OR PLASTIC BACKGROUND OF THE INVENTION The mostdifferent profiles of shoe soles have been known. In choosing the kindof profile, up to now especially the grip of the sole has far more beentaken into consideration than its firmness. A large number of soleprofiles show only transverse rills or grooves mainly running over thewhole width of the sole. In this design, weakened by said rills orgrooves, the sole during walking is stressed to buckling. Inconsequence, such places are especially exposed to get torn.

A further problem especially in soles molded to the shoe from foamingpolyurethane mixtures of relatively low viscosity consists in the fact,that when being poured or injected into the sole mould under only lowpressure, the material is not adequately distributed; various parts ofthe sole mould are not filled at all or only insufficiently. Thereby,air bubbles are entrapped especially at the profile edges near the treadof the sole. In this instance, the material flow by disadvantageousprofile design is retarded.

SUMMARY OF THE INVENTION The invention now refers to a sole and/or aheel of rubber or plastic, especially polyurethane with a treadpreferably roughened or finely profiled and cut by grooves to improvethe grip.

An object of the invention is therefore a soling having a profile whichavoids the above mentioned disadvantages, the material flow not beingretarded, but in contrary is uniformly distributed over the whole solearea. Thereby at least one longitudinal rib is provided in the heel aswell as in the sole, over all its respective length, at some distancefrom the edge and running essentially in the longitudinal direction ofthe shoe. Transverse and/or inclined ribs now branch off thislongitudinal rib running from it and/or from the central line of thesole towards the shoe-tip or forming an angle of maximum 90 andembracing grooves not communicating with each other. This dispositionfurthermore provides a better distribution of stress over the surface ofthe sole, because the buckling cannot appear in a single groove or rill.The longitudinal rib(s) may be straight or slightly bent, or they mayform angles. Said grooves may be of constant depth and/or width over alltheir length, or the depth and the width respectively of the grooves mayvary over their length.

Furthermore, the sole may be designed in such a way, that also thetransverse or inclined grooves are bent, preferably arcuately orsemicircularly, but any tangent to their circumference from thelongitudinal rib and/or the center of sole shall run towards the tip ofthe shoe or form an angle with it of not more than 90. Furthermore thegrooves or rills may branch-off, but also the branches shall not form anangle or more than 90 with the center line ofthe sole.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following, the inventionis described in the drawing by way of examples. There shows FIG. 1 soleaccording the invention in plan view;

FIG. 2 the sole according FIG. 1, in elevation;

FIG. 3 and 4 two further embodiments of the invention in plan view;

FIG. 5 a form of the grooves in cross section;

FIG. 6 another embodiment of the invention;

FIG. 7 and 8 longitudinal sections of grooves;

FIG. 9 and 10 a cross-sectional view of grooves with different widths;

FIG. 11 a further sole according the invention in plan view;

FIG. 12 the sole according FIG. 11 in cross section along the lineXIIXII and FIG. 13 to 19 further soles according the invention in planview.

The profile of the sole according FIG. I and 2 shows two longitudinalribs 3 and 3 running over all the length of heel 1 and sole 2respectively. Grooves 4, 4 branch off these ribs 3,

3 towards the edges of heel l and of sole 2, respectively. These grooves4, 4' forming an angle a of not more than with the longitudinal ribs 3,3. The smaller the angle a, the better the material can flow to the edgeof the sole and fill all cavities. On the other hand, the grip of thesole in the walking direction is being reduced; in consequence anoptimum solution has to be chosen between the two requirements. An angleof not less than about 30 and not more than about 60, preferably about45 has proven to give the best combination of properties.

On the bottom plate of the sole mould, there are ribs, corresponding tothe later formed grooves 4, 4 in the sole, and channels corresponding tothe later sole ribs 8, 17, 21, 26, 27, 30 (see also later figures). Themain stream of the material running thru the longitudinal rib 3, 3 ofthe sole, is bent by the mould ribs and conducted into said channelswithout entrapping air bubbles.

Furthermore, by the inclined position of the grooves, the load duringwalking is better distributed over several ribs. In this way, nobuckling lines are formed as occurs in the cross position of the groovesbecause of the section being reduced.

As illustrated in FIG. 3, the grooves 5 may also run arcuate or curved,e.g. as arcs or semicircles. But any tangent to the circumference of thegrooves 5 shall form an angle a of not more than 90 with the centralline of the sole A or with the corresponding longitudinal ribrespectively.

FIG. 4 is showing a further sole, the grooves 6 of which providebranches 7, but equally form an angle a of not more than 90 with thecentral line A of the sole.

A semicircular cross section of the grooves may be chosen as illustratedby FIG. 5, but the cross section may have any other adequate form aswell, e.g. a rectangular cross section. However, it is important toavoid sharp edges within the grooves, so that no capillary cracks areformed which could destroy the sole very soon. Furthermore, adequatelyrounded mould ribs in the bottom plate are facilitating a better flow ofthe material.

FIG. 6 illustrates a design of sole, with a zigzag central longitudinalrib 3". It is formed by grooves 4 following a mutually alternatingdesign.

Eventual injuries of the sole by small stitches or similar damages thatusually occur under the continued stress lead to an enlargement of saidstitches and further to the total deterioration of the sole. However, inthe sole tread according to the invention, the bending stress duringwalking is transmitted to the thinner portions of the sole in thegrooves, which are situated deeper than the tread of the ribs andtherefore cannot or far less be damaged. Especially in the form of thesole described in FIG. 6, even the longitudinal rib 3" of the treadremains essentially free of such bending stresses.

As shown in FIG. 7, the grooves 4 may become deeper towatds the edge ofthe sole. In this way, the grip of the sole at the edge is improved;furthermore, upon special stress in this part (sports shoes!) a too soonwear and tear are avoided.

Where such a necessity is not given, the form of the grooves may bedesigned as shown in FIG. 8, the grooves becoming deeper towards thecenter of the sole. Upon normal walking, the bending stress for instanceis transmitted to the ball in the central part of the sole. As the soleis most frequently thinner in the middle than on the edges, because of acertain curvature of the shoe last, seen transverse to the walkingdirection, the bending stress during walking will lead to a curvature ofthis central thinner inner ball part, so that it would be worn out morerapidly, compared with the edge of the sole. This can be overcome by anadequate formation of the grooves according FIG. 8.

In a similar way, the sole design may be adjusted also to otherrequirements, e.g. by an increase or reduction of the groove widthtowards the edge of the sole as shown in FIGS. 9 and 10. Especially anincreasing width of the grooves 4 towards the edge of the sole iscounteracting a too rapid blocking of the grooves by earth or snow andso prolongs the grip of the sole.

In the example of a sole according FIGS. 11 and 12, cross ribs branchoff the central, slightly bent longitudinal rib 3, that satisfy therequirement of the angle with the central rib and terminate at two edgeribs 9 and 10. If the grooves 4", which now do not run to the edge ofthe sole, are relatively deep, it is useful to give to the sole in crosssection, a curvature amounting to at, larger than the depth x of thegrooves, preferably at least 1.2 times the depth x of the grooves.

In the sole according FIG. 13, a total of six ribs 11 to 16, of aslightly bent design, are provided in the longitudinal sense, each twoones being separated by a smooth groove and from which various shorttriangular transverse or inclined ribs 17 branch off, directed towardsthe tip of the sole and embracing grooves 31 of also triangular designat the edge of the sole. However, in the middle of the sole, these ribsembrace grooves 32 that show a serrate design.

In FIG. 14, a central rib 3 is provided, from which the grooves 4 branchoff all over the width, whereas other grooves terminate at longitudinalribs 18 and 19 that are situated nearer to the edge of the sole. Fromthe lateral longitudinal ribs 18 and 19, transverse ribs 21 branch offas well, forming an angle of 90 with the longitudinal ribs 18 and 19.

FIG. 15 represents the plan view of another sole, only providing twolateral longitudinal ribs 18 and 19. Towards the edge of the sole, opengrooves 4, but towards the center of the sole grooves 22-which areclosed in themselves and converge towards the tip of the shoe-branch offsaid ribs 18 and 19.

In the sole according to FIG. 16, grooves 23 branch off a centrallongitudinal rib 3" of slightly arcuate or angular design. The firstportion 24 of said grooves 23 embraces an angle of not more than 90 withsaid longitudinal rib, but their exterior portion 25 directed towardsthe edge of the sole bends slightly back, to improve the grip in walkingdirection.

FIG. 17 represents an especially advantageous form of the presentinvention. Here, the central longitudinal rib 3", running over all thelength, has a somewhat more essentially angular design. Ribs 26 and 27branch off this rib and form an angle of 90. Due to the angular positionof the middle rib 3", however, the first portion of said ribs 26 and 27indeed is inclined towards the tip of the shoe, whereas their exteriorportion, directing towards the edge of the sole, is situatedapproximately transversely to the walking direction, in order to improvethe grip of the sole tread. Thereby, ribs 27 may be provided as well,that branch in such a way, that two or more outer portions 28 of saidribs 27 are situated transversely, beginning from the inner, inclinedportion. Nevertheless, all these ribs are embracing grooves 4",separated from each other.

In the representation of FIG. 18, ribs 8 and grooves 4" branch off theslightly, angular longitudinal rib 3 but do not run to the edge of thesole; they are limited there by two longitudinal ribs 9 and 10. -In theform of FIG. 19, grooves 29 branch ofi a straight central longitudinalrib 3 and run angularly up to the edge of the sole, forming steps, everyportion forming an angle a of less than with the central line of thesole.

Such a formation of the tread has the advantage, that step edges 33 areformed in the inclined, step-shaped ribs 32 which are embraced bygrooves 29. Said edges 33 run more or less parallel to the edge of thesole, allowing a special grip of the complete length of the unit in thelengthwise direction of the unit and spaced at a distance from the sideedges of the unit, a

plurality of rib members branching off said longitudinal rib, and allextending in concert towards the tip of the unit and forming an includedangle of less than 90, a plurality of grooves provided in the treadface, said plurality of grooves non-communicating with one another andbounding said rib members, said grooves being positioned in alternatelateral spaces across the longitudinal rib in the longitudinaldirection.

2. The footwear as defined in claim 1, wherein the depth of said groovesvaries from the center to the side edges of the unit.

3. The footwear as defined in claim 1, wherein the width of said groovesvaries from the center to the side edges of the unit.

4. The footwear as defined in claim 1, wherein said grooves are arcuate.v

5. The footwear as defined in claim 4, wherein a tangent to the outsidesurface of any groove extends in the direction of the tip of the unitand forms an angle with said longitudinal rib which is less than 90.

6. The footwear as defined in claim 1, wherein said grooves beingprovided with branches forming an angle with respect to said ribmembers.

7. The footwear as defined in claim 1, wherein said rib membersbranching ofi said longitudinal rib form an angle of betweenapproximately 30 and 60 with respect to said longitudinal rib.

8. The footwear as defined in claim 7, wherein said angle isapproximately 45.

1. In footwear, especially a shoe, the combination of a sole and heelunit formed of a material selected from rubber or plastic, especiallypolyurethane, a tread face provided along the sole and heel, at leastone longitudinal rib provided in the tread face, said longitudinal ribextending throughout the complete length of the unit in the lengthwisedirection of the unit and spaced at a distance from the side edges ofthe unit, a plurality of rib members branching off said longitudinalrib, and all extending in concert towards the tip of the unit andforming an included angle of less than 90*, a plurality of groovesprovided in the tread face, said plurality of grooves non-communicatingwith one another and bounding said rib members, said grooves beingpositioned in alternate lateral spaces across the longitudinal rib inthe longitudinal direction.
 2. The footwear as defined in claim 1,wherein the depth of said grooves varies from the center to the sideedges of the unit.
 3. The footwear as defined in claim 1, wherein thewidth of said grooves varies from the center to the side edges of theunit.
 4. The footwear as defined in claim 1, wherein said grooves arearcuate.
 5. The footwear as defined in claim 4, wherein a tangent to theoutside surface of any groove extends in the direction of the tip of theunit and forms an angle with said longitudinal rib which is less than90*.
 6. The footwear as defined in claim 1, wherein said grooves beingprovided with branches forming an angle with respect to said ribmembers.
 7. The footwear as defined in claim 1, wherein said rib membersbranching off said longitudinal rib form an angle of betweenapproximately 30* and 60* with respect to said longitudinal rib.
 8. Thefootwear as defined in claim 7, wherein said angle is approximately 45*.